nitpick: remove asyncio from requirement.txt

[deependujha]

Before submitting

• Was this discussed/agreed via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

What does this PR do?

asyncio is part of the Python standard library (since 3.4).

Our supported Python versions (3.9–3.13) already include it, so it doesn’t need to be listed as an install requirement.

PR review

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
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⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

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